Propelling device for aircraft and the like



Aug. 11, 1931. w, STELZER 1,817,952

PROPELLING DEVICE FOR AIRCRAFT AND THE LIKE Filed Sept. 25, 1929 atentedAug. ll, l3l

WILLIAM S'I'EZER, F CHICAGO, ILLINOIS, ASSIGNOB. T0 AMERICAN PROPEIILERCOM- PANY, 0F BALTIMORE, MARYLAND, A COR-EORATION 0F MARYLAND PROEELLINGDEVICE FOR AIRCRAFT AND THE LIKE Application filed September 25,- 1929.Serial No. 394,987.

The invention relates to improvements in aircraft and the like and moreparticularly to a device for driving aplurality of propellers with asingle power unit, where power is g, transmitted from said power unit tothe pro pellers by means of cranks or eccentrics.

The object of the invention is to provide an eficient propelling devicefor aircraft or watercraft.

The present invention shows a further embodiment of the invention shownin my application for patent filed September 3, 1929,

Serial Number 389,981 and is therefore related to that invention as faras the employan ment of a water propeller in conjunction with ahydroplane is concerned. However, the

principal object of this invention is to provide effective means foractuating a plurality otpropellers, where a single power unit is m used.'A further important obj ect is the elimination of gears.

Another object is to increase the propeller disk area and to reduce thevelocity of the blades. This object cannot be obtained with "at presentmethods unless a speed reducing mechanism is employed, or it thepropellers are mounted in tandem. The latter arrangement does not afiordan increase in the efiective propeller disk area, because the quangagtity of air accelerated is not larger. 1 have therefore devised apropelling mechanism where the propellers are mounted parallel. Counterpropeller action is made efi'ective by placing the propellers closetogether. As

each propeller takes up only a fraction of the total power output of theengine, and thereby may be of smaller diameter, the same result isobtained as with a reducing mechanism, which permits the use of a highspeed engine without reducing the propeller efficiency.

The device shown is of simple and inexpensive construction and istherefore superior to a speed reducing mechanism.

A further object is to provide an improved starting device for aircraftas the thrust produced by the air propellers is augmented by the liftand thrust produced by the water propeller.

The invention also aims to provide propelshown diagrammatically andtherefore do not disclose structural details in proper form orproportion.

The terms employed herein are used in the generic and descriptive sense,and therefore are not intended primarily as terms oi limitation.

The power unit or engine 2 by means of its crank shaft 3 turns the drivecrank d journaled in the housing 5 which is rigidly secured to thecrankcase of the engine 2 and may consist of several parts to permitassemblage. 'lhis housing '5 merely serves as a.

support for the mechanism and as a container for the luhricating oil. Itis therefore apparent that said housing may he part of the engine orcrankcase or that the entire mechanism may he within the crankcase,depending on the type or engine used.

The plate or frame 6 adapted to receive the crank pin of said crank 4and the crank pins of propeller cranks 7, 7 transmits power from saiddrive crank lto said propeller cranks 7, 7, whose journals 8, 8 areparallel to the crank shaft 3 and revolubly supported at 9, 9 to drive apair of air propellers 10, 10 by means of propeller shafts ll, 11supported in intermediate bearings 12, 12, 13, 13, and 1d, 14..Universal joints 15, 15 are interposed hetween the journals 8, 8rand thepropeller shafts ll, 11 to permit-obli hetween the two propeller shafts."ihus the cranlr mechanism may he of very compact construction withoutlimiting the size of the propellers l0, 10.

Figure 2 gives a better illustration of the arrangement of the cranks 7,7 and the plate E servers 6. The former are provided with counterweights to counterbalance the plate 6 which is built of light materialor constructed as a rigid frame provided with. bearings for the crankpins of the cranks 7, 'Z and d. The said bearings are preferablyanti-friction bearings, however, ordinary bearings have been shown asthe details of construction have no connection with the spirit and scopeof the invention.

The journal of the drive crank lis extended and serves as a propellershaft 3.6 axially aligned with the crankshaft or engine shaft 3, drivingthe water propeller 17 which is keyed to it. Therefore, the pro pellershaft 16 may be considered as a continuation of the engine shaft 3.

The device is shown embodied in a hydroplane, where 18, 18 are thewings, 19 the hull or body structure and 20, 20 joists ior supportingthe air propellers 10,16. Said joists are of unequal length to preventinterference between the propeller blades. It will be noticed from thedrawings that the blades acting on the same area move in oppositedirections and therefore provide the desirable counter propeller action.

While I have herein shown and described a single embodiment of theinvention as a plied to a specific type or" aircraft, I wish to make itclearly understood that the invention can be carried out in waysdifferent from that shown without departing from the spirit and scopeofthe invention. The primary idea is to provide a plurality ofpropellers, and it may readily be seen from the drawings that theprinciple may he applied in a device to actuate any number ofpropellers, provided the plate 6 is made large enough. It is merelynecessary to support said plate 6 with at least three cranks to providefaultless 0 oration. If onl two cranks were used, 1: iere would be adisad point and the device would not be dependable any more.

A further modification might be to place the crank mechanism forward ofthe engine 2. If the device is embodied in a land plane, said waterpropeller 17 may be replaced by one or more air propellers, or it may beleft od' entirely.

It is also apparent that the same results may be obtained by usingeccentrics instead of the cranks 7, 7 and l.

Further embodiments, modifications, and variations may be resorted towithin the scope and s irit of the invention as here claimed:

1. n a device for the propulsion of aircraft in combination, an enginehaving a drive shaft, a drive crank actuated by said drive shaft, awater propeller shaft axially aligned and connected to said drive shaft,means for rotatably supporting said water propeller shaft, a waterpropeller connected to said water propeller shaft, a pair of: propellercranks arranged parallel to said drive shaft,

a frame adapted to receive the crank pins of said propeller cranks andsaid drive crank to transmit power from said drive crank to said roteller cranks a air of ro eller P P a P P shafts actuated by saidpropeller cranks, universal joints intermediate said propeller cranksand said propeller shafts, an air pro peller mounted to each of saidpropeller shafts, and means for rotatably supporting said propellershafts and the journals of said a propeller cranks.

2. in a device for the propulsion or aircraft, a driving motor, a casingattached thereto, shaft driven by said motor and extending through saidcasing, a water propeller carried by said shaft, a crank on said shaftwithin said casing, a plurality of shafts journaled in said casing, saidshafts being parallel to said first-named shaft, cranks carried by allof said shafts and being disposed

